John Adams's Doctor Atomic, which has its British premiere tonight at the Coliseum in London in Penny Woolcock's production, is everywhere in the media at the moment. And from most of the coverage about it, you'd think that the opera was a historical lecture on the ethics of the atomic age, with the Faustian figure of J Robert Oppenheimer leading his team of nefarious scientists at Los Alamos to the possibility of total annihilation, and the creation of the bombs that would destroy Hiroshima and Nagasaki.

In his interview in G2 today, Martin Kettle asks the key question of baritone Gerald Finley, who plays Robert Oppenheimer (and who's sung the role in every single performance of the opera there's ever been since its premiere in San Francisco in 2005): "How can even the most powerful music or the most imaginative staging avoid making such an epochal subject banal?" Finley's answer – basically, that music can deal with the biggest subjects of life and death, so why shouldn't it deal with the atomic age? – is right on the money. But to me, the most interesting thing about Doctor Atomic won't be what it has to tell me about the Manhattan Project (which is what you might expect, if you heard Penny Woolcock talking on this week's Start the Week), but whether it works as a piece of music theatre. If you want the real, historical lowdown on Oppenheimer and Los Alamos, the best book I've found is Kai Bird and Martin J Sherwin's American Prometheus: The Triumph and Tragedy of J Robert Oppenheimer, a meaty 700-page biography that's also a thrilling scientific and political page-turner. The book gives you infinitely more detail and complexity on Oppenheimer as man and scientist than Adams can hope to.

But guess what: that's not the point of opera. The Oppenheimer in Doctor Atomic is not the real Robert Oppenheimer, any more than the Nixon in Adams's first opera, Nixon in China, was the historical Richard J Nixon. Oppenheimer becomes a mythic figure on stage, his moral and human dilemmas (or rather, those that Adams imposes upon him) explored and exploded within the frame of the opera house. At least they should be: tonight will tell whether Adams's music works, whether he creates a score that transcends the immediate concerns of his characters and resonates with audiences more profoundly, or whether he is swamped by the massive, fissile freight of his material.